01 - Preheat oven to 425°F (220°C). Line a large sheet pan with parchment paper for easy cleanup.
02 - In a medium bowl, vigorously whisk together white miso paste, honey, soy sauce, rice vinegar, sesame oil, minced garlic, and grated ginger until a smooth, cohesive glaze forms.
03 - Thoroughly pat the chicken thighs dry using paper towels. Rub each thigh with 1 tablespoon of olive oil and season lightly with salt and freshly ground black pepper. Arrange the chicken thighs, skin-side up, on one half of the prepared sheet pan.
04 - Generously brush half of the prepared miso honey glaze over the chicken thighs, ensuring even coverage.
05 - In a separate large bowl, combine the cubed butternut squash, halved Brussels sprouts, red onion wedges, and sliced carrots. Drizzle with 2 tablespoons of olive oil and season with salt and pepper. Toss well to coat all the vegetables.
06 - Spread the seasoned vegetables evenly on the remaining half of the sheet pan, adjacent to the chicken. Place the sheet pan in the preheated oven and roast for 20 minutes.
07 - Carefully remove the sheet pan from the oven. Brush the chicken with the remaining miso honey glaze. Gently stir the vegetables to ensure even cooking and caramelization.
08 - Return the sheet pan to the oven and continue roasting for an additional 15 minutes. The chicken should be cooked through with an internal temperature of 165°F (74°C), and the vegetables should be tender and caramelized.
09 - Remove the sheet pan from the oven. Transfer the chicken and roasted vegetables to serving plates. Garnish with chopped fresh parsley and toasted sesame seeds, if using. Serve immediately.